The false flowers or pseudanthia of all Euphorbia species are in fact real flowers, just several of them clustered closely together, looking like one flower. Individually a cyathium performs exactly the same seed producing function as all flowers do. Daisies or proteas are also pseudanthia, referred to as flowerheads, comprising many small, individual flowers forming one inflorescence or pseudanthium.
The green female cyathia flanking the larger yellow male ones in the photo don’t have petals, but fleshy glands surrounding the vital reproductive parts. The female ones here are single flowers, another quirk of the botanical nomenclature (Wikipedia; Coates Palgrave, 2002).